An Electroencephalography Investigation of the Differential Effects of Visual versus Auditory Attention on Crossmodal Temporal Acuity

Abstract

Our perception of the world hinges on our ability to accurately combine the many stimuli in our environment. This multisensory integration is highly dependent on the temporal relationship between unisensory events and our brain's ability to discern small timing differences between stimuli (crossmodal temporal acuity). Our previous research investigated whether attention alters crossmodal temporal acuity using a crossmodal temporal order judgment (CTOJ) task in which participants were asked to report if a flash or beep occurring at different time intervals appeared first while concurrently completing either a visual distractor or auditory distractor task. We found that increasing the perceptual load of both distractor tasks led to sharp declines in participants' crossmodal temporal acuity. The current study uses electroencephalography (EEG) to understand the neural mechanisms that lead to decreased crossmodal temporal acuity. Participants completed a CTOJ task in association with a visual distractor task, as described above, while EEG activity was recorded from 64 scalp electrodes. EEG activity was averaged based on the onset of the flash, producing an event-related potential (ERP) waveform for each perceptual load level and stimulus onset asynchrony (SOA) combination. Preliminary data analysis suggests that increasing perceptual load most strongly influences the amplitude of the N1/P2 complex in response to the flash across parietal electrodes. This suggests that decreases in crossmodal temporal acuity with increasing visual load may be mediated by alterations in visual processing. Ongoing data collection investigates whether increasing auditory load will lead to alterations in auditory processing, thus suggesting a modality-specific mechanism for disruptions in crossmodal temporal acuity. This line of research serves to illuminate the neural networks that underlie the interaction between attention and multisensory integration.

Publisher

Association for Research in Vision and Opthalmology

Publication Date

9-1-2018

Publication Title

Journal of Vision

Department

Neuroscience

Document Type

Abstract

DOI

https://dx.doi.org/10.1167/18.10.1142

Language

English

Format

text

Link to Full Text

Share

COinS